Is there an RSS feed for the forums?

There is.
If you look closely you will spot a RSS icon on the top right of this site which allows you to subscribe to this thread.
You can also subscribe to specific categories if you want something like that.
However you're most likely searching for a "all topics" feed. If you navigate to the recent topics site (in the title bar on desktop, the sidebar on mobile) you will find an icon there too.

Yeah, as @RoiEX mentioned you can subscribe to a number of different RSS feeds depending on what you want (specific thread vs category vs recent, etc). Here is a quick screenshot of where you could find the RSS feed icon for all recent posts: